Re: [PATCH] powerpc/book3s64/radix/tlb: Determine hugepage flush correctly
From: Nicholas Piggin <npiggin@gmail.com>
Date: 2020-05-13 04:32:35
Excerpts from Aneesh Kumar K.V's message of May 13, 2020 1:06 pm:
With a 64K page size flush with start and end value as below (start, end) = (721f680d0000, 721f680e0000) results in (hstart, hend) = (721f68200000, 721f68000000) Avoid doing a __tlbie_va_range with the wrong hstart and hend value in this case. __tlbie_va_range will skip the actual tlbie operation for start > end. But we still end up doing the tlbie fixup.
Hm, good catch.
quoted hunk ↗ jump to hunk
Reported-by: Bharata B Rao <redacted> Signed-off-by: Aneesh Kumar K.V <redacted> --- arch/powerpc/mm/book3s64/radix_tlb.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)diff --git a/arch/powerpc/mm/book3s64/radix_tlb.c b/arch/powerpc/mm/book3s64/radix_tlb.c index 758ade2c2b6e..d592f9e1c037 100644 --- a/arch/powerpc/mm/book3s64/radix_tlb.c +++ b/arch/powerpc/mm/book3s64/radix_tlb.c@@ -884,10 +884,10 @@ static inline void __radix__flush_tlb_range(struct mm_struct *mm, if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE)) { hstart = (start + PMD_SIZE - 1) & PMD_MASK; hend = end & PMD_MASK; - if (hstart == hend) - hflush = false; - else + if (hstart < hend) hflush = true; + else + hflush = false;
We can probably get rid of the else part since it is already false. Otherwise Reviewed-by: Nicholas Piggin <npiggin@gmail.com>